Composite testing
Composite testing
Keywords: Testing, Composites, Aerospace
The installation of another large testing machine has reportedly raised mechanical testing capacity by at least a third at Ireland’s composites Testing Laboratory in Galway.
For loads up to 250 kN, the new floor-mounted, twin-column universal tester from Zwick joins two existing testing systems – both high-capacity to provide a needed additional resource to cope with an expanding long-term order book.
One of the few specialist laboratories to focus mainly on the certification and qualification of composites, CTL will use the machine for an unusually broad range of mechanical tests on carbon-reinforced plastics and glass-fibre-reinforced plastics, most of them for employment in aerospace technology.
Carried out to EN, ISO, BS and Airbus Industries specifications, the procedures include tensile, compression, shear, fatigue, flexure, interlaminar and other tests on site specimens supplied by CTL customers or made in the company’s own workshop.
To enable specimens to be tested realistically at or near actual working temperatures, the machine is equipped with a temperature chamber.
CIL says that the work requires high rigidity in machine construction with extremely accurate alignment precision. Zwick’s flexible “testXpert”software was also judged to be the easiest to use of those examined, allowing standard tests to be set up quickly and accurately, with comprehensive reporting of results visually and on hard copy.
CIL grew out of a material-development project between the National University of Ireland (Galway), Airbus UK Limited and the Irish Government. Achieving ILAB accreditation under the European Accreditation of Laboratories scheme, the company was formed in 1999 to provide specialised services in the mechanical, environmental and physical testing of composites.
Zwick Roell also report that its new tabletop system form is said to speed up and cut the cost of fatigue testing smaller components and structures.
Thought to be the first of its type, the machine owes its performance to a novel electromagnetic drive – rather than servo hydraulic – for applying loads. This feature is said to enable fatigue tests to be carried out at frequencies two to three times higher than equivalent servo hydraulic systems with much reduced test times and lower energy consumption.
Called Vibrophore Amsler HFP5100, the new machine is rated for static loads from 1 to 20 kN and dynamic loads from 0.5 to 10 kN at test frequencies from 30 to 300 Hz.
It comprises of a two-column loading frame incorporating an independent magnetic interferric drive linked to a dedicated electronic measurement and control unit with a monitor.
Expected to appeal particularly to test engineers in the aerospace and finishing industries, the Vibrophore system is designed to apply sinusoidal dynamic and static loads to the specimen – together or separately –with either load regulated independently and continuously.
Typical applications include the determination of fatigue strength in temporary and permanent resistance, K values and crack propagation, together with the generation of initial cracks in fracture-mechanics specimens and impact-testing specimens.
Engineered to be maintenance-free, vibrophore is believed to be lower in first cost than servo hydraulic machines of comparable capacity and rating.
Details available from: Zwick Testing Machines Ltd. Tel: +44 (0)1568 615201.
